A method for the detection of arsenocholine(AsC), arsenobetaine(AsB), As(Ⅲ), dimethylarsinic(DMA), monomethylarsonic(MMA) and As(Ⅴ) by capillary electrophoresis-inductively coupled plasma mass spectrometry(CE-ICP-MS) was established. The results showed that the six species of arsenic were separated within 20 min under the optimized conditions. Good linearities of 6 arsenic species were observed in the range from 2 to 50 μg·L-1 with the linear correlation greater than 0.996, the detection limits were 0.10~1.08 μg·L-1 and the RSDs (n=5) of the peak areas were smaller than 7%. The method was successfully adopted to the determination of the species in scomberomorus niphonius. The recoveries were between 93% and 98%, and we found the arsenobetaine(AsB) was the main species in the sample. The method was suitable for the analysis of other biological samples with the advantages of good stability, less sample consumption, short analysis time and convenience.